Method and apparatus for determining changes in the longitudinal dynamic behavior of a railway vehicle

Abstract

A method for determining changes in the longitudinal-dynamic behavior is disclosed, in particular of an undercarriage, of a railway vehicle for identifying a current driving condition of the railway vehicle, wherein variables, which cannot be measured and which characterize the longitudinal-dynamic behavior, are reconstructed and evaluated via a system model of the railway vehicle by means of a cybernetic observer from a known or metrologically determined input signal and at least one measuring signal of the observed railway vehicle as an observed real reference system. The at least one measuring signal of the observed railway vehicle and a corresponding reconstructed measuring signal of the system model are compared and the deviation determined by comparison is recursively tracked with a regulator so that the determined deviation is minimized.

The invention claimed is: 
     
       1. A method for determining changes in longitudinal-dynamic behavior, in particular of an undercarriage, of a railway vehicle for identifying a current driving condition of the railway vehicle, comprising:
 wherein variables, which cannot be measured and which characterize the longitudinal-dynamic behavior, are reconstructed and evaluated via a system model of the railway vehicle by means of a cybernetic observer from a known or metrologically determined input signal and at least one measuring signal of the observed railway vehicle as an observed real reference system, 
 wherein the at least one measuring signal of the observed railway vehicle and a corresponding reconstructed measuring signal of the system model are compared and a deviation determined by comparison is recursively tracked with a regulator so that the determined deviation is minimized. 
 
     
     
       2. The method according to  claim 1 , wherein the input signal is additionally supplied to the system model. 
     
     
       3. The method according to  claim 1 , wherein the input signal and/or the at least one measuring signal are detected at one or more of the following components:
 a railcar body; 
 an undercarriage of the railway vehicle; 
 at least one bogie of the railway vehicle; 
 at least one wheelset of the railway vehicle. 
 
     
     
       4. The method according to  claim 3 , wherein the at least one measuring signal is detected simultaneously on opposite sides of the undercarriage or the bogie or the wheelset. 
     
     
       5. The method according to  claim 1 , wherein a brake pressure of a brake actuator or a brake current for generating a braking force decelerating the railway vehicle is processed as the input signal. 
     
     
       6. The method according to  claim 1 , wherein a driving force or a motor current for generating a force which accelerates the railway vehicle is processed as the input signal. 
     
     
       7. The method according to  claim 1 , wherein a rotational speed or a change in rotational speed of at least one wheelset is processed as the at least one measuring signal. 
     
     
       8. The method according to  claim 1 , wherein a strain of a component which transmits a longitudinal force, in particular a pull/push-rod or a pivot pin or a lemniscate lever or a wheelset guide, is processed as the at least one measuring signal. 
     
     
       9. The method according to  claim 1 , wherein a spring deflection in one or more spring stages is processed as the at least one measuring signal. 
     
     
       10. The method according to  claim 1 , wherein the evaluation of the variables characterizing the longitudinal-dynamic behavior comprises a comparison of the variables of successive undercarriages or railcar bodies or wheelsets. 
     
     
       11. A computer program product which can be loaded directly into the internal memory of a digital control unit and comprises software code segments which, when the product runs on the control unit, carry out the method according to  claim 1 . 
     
     
       12. An apparatus for determining changes in the longitudinal-dynamic behavior, in particular of an undercarriage, of a railway vehicle for identifying a current driving condition of the railway vehicle, comprising:
 a control unit and at least one sensor unit for providing a respective measuring signal, wherein the control unit is configured to reconstruct and evaluate variables, which cannot be measured and which characterize the longitudinal-dynamic behavior, via a system model of the railway vehicle by means of a cybernetic observer from a known or metrologically determined input signal and the at least one measuring signal of the observed railway vehicle as an observed real reference system, 
 wherein the control unit is further configured to compare the at least one measuring signal of the observed railway vehicle and a corresponding reconstructed measuring signal of the system model and to recursively track, with a regulator, the deviation determined by comparison so that the determined deviation is minimized.